Atmospheric microplastics serve as unique microbial niches, facilitating the formation of plastispheres. However, their microbial succession dynamics and associated health risks remain poorly characterized. To address these critical knowledge gaps, this study employed a two-month outdoor in-situ cultivation experiment, focusing on comparing bacterial colonization patterns on microplastics, natural and non-plastic substrates. Plastic-associated communities initially displayed polymer-specific colonization traits. Over time, these communities gradually converged, forming highly similar compositions. Functionally, the relative abundance of chemoheterotrophic pathways declined over time, while the proportion of light-dependent processes increased notably. Seven pathogenic species were specifically enriched on plastic substrates, of which four were detected only in later stages, indicating potential pathogen accumulation during biofilm maturation. Despite a decrease in the relative abundance of pathogens, the protective biofilm microenvironment may sustain their transmission risks. This study highlights the unique role of atmospheric microplastics as bacterial carriers, elucidating key aspects of their succession dynamics and health implications, highlighting the adaptive role of photoautotrophy under atmospheric stressors. It provides important insights for in-depth understanding of the environmental and health effects of atmospheric microplastics.

Phosphorus (P)-driven eutrophication remains a major ecological threat to aquatic ecosystems, particularly in intensively farmed regions. However, the relative contributions of agricultural legacy P and internal sediment-derived P remain poorly constrained due to complex transformation pathways and the lack of integrated source-tracing approaches. In this study, we combined chemical fractionation, phosphate oxygen isotope (δ18OP) tracing, and high-resolution molecular characterization to identify dominant P sources and their bioavailability in Nanyihu Lake, China. Results from lake and estuarine sediments, as well as adjacent agricultural soils, indicate that labile (LP) and moderately labile phosphorus (MLP) are the main bioavailable fractions. Bayesian mixing models indicate that agricultural sources attributed 46 % of total P inputs, including agricultural soils (25 %) and feces (21 %), exceeding contributions from internal sediment release (38 %) and wastewater treatment plants (16 %). In situ profiling using diffusive gradients in thin films (DGT) and Peeper methods reveals that iron (oxy)hydroxide reduction facilitates sedimentary P release, with soluble reactive phosphorus (SRP) fluxes reaching 6.32 ± 0.11 mg m-2d-1, underscoring its substantial role in annual internal P loading. Furthermore, Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) indicates that lipid- and protein-like organic P compounds in sediments can be readily mineralized, continuously replenishing bioavailable P pools. These findings demonstrate that agricultural activities not only drive external P loading but also promote accumulation of reactivatable P in sediment, sustaining internal P cycling and long-term eutrophication. Effective watershed management requires integrating control of external inputs and sediment legacy P across the landscape.

The contamination of water bodies by ciprofloxacin (CIP) poses a significant threat to global health and ecosystem safety. This study converted Tenebrio molitor frass - a unique and sustainable insect waste - into a novel iron-nitrogen functionalized biochar (Fe-N-BC) catalyst via one-step pyrolysis for efficient peroxymonosulfate (PMS) activation to degrade CIP. The Fe-2.5@N-BC catalyst exhibited a unique porous structure and high defect density, enabling 96.7% CIP removal within 30 min. The system maintained high efficiency over a wide pH range (3-11) and in complex water matrices, demonstrating excellent practical applicability. Radical quenching experiments, electrochemical tests, and DFT calculations revealed that the degradation was governed by a synergistic mechanism of both radical (center dot OH, center dot SO4- and center dot O-2(-)) and non-radical (Fe(IV) and O-1(2)) pathways, where Fe(IV) served as the dominant species. The degradation pathways of CIP were proposed, and toxicity evaluation suggested effective detoxification of the solution. The catalyst also showed excellent stability, reusability, and effectiveness against other antibiotics. This work provides a novel waste-to-wealth strategy for environmental remediation and offers profound insights into the Fe(IV)-dominated non-radical oxidation process in PMS activation.

We present an expert-free, end-to-end deep learning framework for the simultaneous quantification of three fluorescent organic micropollutants (OMPs)-ciprofloxacin (CIP), naproxen(NAP), and zolpidem(ZOL)-directly from standardized excitation-emission matrix (EEM) spectra. Using a publicly available data set of natural water and municipal wastewater samples spiked with target compounds (0-50 mu g L-1), a lightweight convolutional neural network achieves robust multitarget prediction with a mean overall out-of-fold R-2 of 0.984 (CIP: 0.978, NAP: 0.980, ZOL: 0.993) using repeated stratified 5-fold cross-validation, without requiring PARAFAC decomposition or expert-guided spectral interpretation. Prediction accuracy is concentration-dependent, demonstrating practical utility predominantly at moderate-to-high levels (>5 mu g L-1), particularly for highly fluorescent compounds. While detection limits (1.0-3.8 mu g L-1) preclude routine monitoring of trace environmental concentrations, this framework offers a rapid, automated complementary approach to chromatography for process monitoring in high-strength wastewater streams (e.g., industrial effluents or WWTP influents) and data-intensive laboratory investigations into OMPs fate and removal.

A novel magnetic CoNi@CN catalyst was synthesized through controlled pyrolysis of a cucurbit[7]uril (CB[7]) derived supramolecular precursor, wherein the self-assembly between CB[7] and metal ligands yielded a cage-confined framework that precisely regulated bimetallic coordination. This confinement strategy resulted in an ordered nitrogen-doped graphitic carbon matrix embedded with uniformly distributed CoNi nanoclusters (10-20 nm). Despite its moderate specific surface area (23.47 m2/g) and hierarchical pore structure (micropores: 0-10 nm; mesopores: 40-80 nm), the catalyst demonstrated exceptional activity, achieving over 99 % degradation of tetracycline hydrochloride (TCH) within 25 min in a peroxymonosulfate (PMS) activation system. Mechanistic studies confirmed a non-radical pathway mediated by 1O2and electron transfer, facilitated by redox cycling of Co2+/Co3 + and Ni2+/Ni3 +. Density functional theory analysis further supported the transfer of 0.75 electrons from CoNi@CN to PMS, promoting 1O2generation. The catalyst exhibited excellent reusability (88.6 % efficiency after five cycles), pH adaptability (pH 3-12), and magnetic recoverability (saturation magnetization = 2.96 emu/g). This work highlights the importance of CB[7]-mediated structural confinement in preventing metal agglomeration and enabling efficient PMS activation, offering valuable insights for the rational design of bimetallic catalysts for environmental remediation.

There is a significant gap in understanding how crop residues with varying carbon-to-nitrogen (C/N) ratios mitigate soil acidification in acidic soils, particularly considering the complex interplay between soil C chemistry, pH, nutrient dynamics, and their subsequent effects on microbial community composition and enzymatic activities. Here, a 65-day incubation experiment was conducted using four crop residues with varying C/N ratio (rapeseed cake 7.6; peanut straw 27.0; rice straw 48.6 and wheat straw 93.6), aiming to fill these knowledge gaps in the two typical acidic long-term tea garden soils. Results showed that the incorporation of crop residues significantly enhanced edaphic characteristics and mitigated soil acidification. In strongly acidic soil (pH 4.12), rapeseed cake increased SOC recalcitrance, while promoting SOC decomposition in slightly acidic soil (pH 4.75). Furthermore, residue incorporation markedly altered microbial community composition, notably reducing fungal-to-bacterial and G+-to-G− ratios in slightly acidic soil. Soil C chemistry, the primary factor, interacting with pH and nutrients influenced microbial composition and enzymatic activities. Specifically, in strongly acidic soils, microbial composition was determined by the interaction of pH and C chemistry, whereas in slightly acidic soils, it was driven by the interaction between C chemistry and phosphorus content. Correspondingly, enzyme activities were influenced by the interaction of C chemistry with phosphorus in the former soils and nitrogen in the latter soils. Overall, our findings confirm the importance of rapeseed cake in enhancing soil multifunctionality, especially in strongly acidic soil, and highlight the critical role of C chemistry, soil pH, and nutrient interactions in shaping microbial composition and function in acidic soils.

The uprecycling of hydrothermal liquid waste-derived artificial humic acids into stable carbon materials is helpful for advancing the development of hydrothermal carbonization technology, but it has rarely been investigated. For the first time, a multistep pyrolysis method was designed to convert artificial humic acids into honeycomb-like porous carbons (PCs). The obtained PCs exhibited a high specific surface area, reaching 1728.55 m2/g, while nonactivation treatment still provided a high value of 1425.14 m2/g. The hightemperature pyrolysis process yielded graphite-like structures and maintained surface functional groups. PCs have been applied as sorbents to remove the emerging plasticizer diethyl phthalate (DEP) in water environments and exhibit promising sorption capabilities (as high as 993.30 mg/g), which are much higher than those reported for other sorbents. The sorption rate was controlled by mass transfer and chemical-like sorption, whereas the sorption capability was controlled mainly by the adsorption process, especially pore filling. Partitioning, hydrogen bonding, pore filling and it-it stacking are possible sorption mechanisms. In addition to the specific surface area, the pore volume is a suitable parameter for assessing the sorption capability. Exogenous dissolved organic matter can affect the sorption of DEP onto PCs through cosorption and coverage of their surface, but its influence is limited. Excellent sorption performance can cover a wide range of pH conditions. The prepared PCs also showed notable reusability and practicality. In this study, an excellent method was proposed for recycling hydrothermal liquid waste and preparing PCs, and the prepared PCs exhibited great potential for environmental remediation.

Robust, national-scale quantification of soil organic carbon (SOC) dynamics in China’s paddy fields has been hindered by widely divergent estimates and a lack of comprehensive driver attribution. To address this, we developed a new empirical model from a comprehensive database of 746 long-term field observations (125 sites) to identify predominant drivers and quantify national-scale SOC stock dynamics from 1980 to 2018. The model explained 43% of the variance in topsoil SOC change. Organic matter input was the dominant driver (21.83% variance), with livestock manure demonstrating the highest C sequestration efficiency, followed by green manure and straw. Soil pH, latitude (as a climate proxy), and initial SOC content were also critical controllers. We estimate that China’s paddy topsoils (0–20 cm) acted as a significant C sink from 1980 to 2018, accumulating 242.51 ± 85.80 Tg C (an average rate of 6.65 Tg C yr−1), bringing the 2018 national stock to 1220.48 ± 85.80 Tg C. Spatially, sequestration was highest in central (e.g., Hunan) and northeastern (e.g., Heilongjiang) China, while Chongqing experienced a net SOC loss. Crucially, our study provides a new long-term benchmark that reconciles previous, higher estimates from shorter timeframes, empirically demonstrating that sequestration rates are non-linear and diminish over time. These findings confirm that the C sequestration potential of paddy soils, while substantial, is finite and requires spatially targeted management of organic inputs and soil pH to maintain.

In-depth analysis of the evolution of ecosystem services (ESs) in the basin at different spatial scales, scientific identification of ecosystem service clusters, and revelation of their spatial and temporal characteristics as well as coupling mechanisms of interactions are the key prerequisites for effective implementation of ES management. This paper assessed the spatial and temporal changes of six key ESs covering food provisioning (FP), water yield (WY), soil retention (SR), water conservation (WC), habitat quality (HQ), and carbon sequestration (CS) in the Xijiang River Basin (XRB), China, between 2000 and 2020. Given that the scale effects of ESs and their spatial heterogeneity in the XRB are still subject to large uncertainties, a combination of Spearman correlation analysis and geographically weighted regression (GWR) modelling systematically revealed the trade-offs and synergistic relationships between ESs and the scale effects from a grid, watershed, and county perspective. Additionally, we applied the self-organizing mapping (SOM) method to identify multiple ecosystem service bundles (ESBs) and propose corresponding sustainable spatial planning and management strategies for each cluster. The results reveal the following key findings: (1) Spatial distribution and heterogeneity: The six ESs demonstrated pronounced spatial variability across the study area during the two-decade period from 2000 to 2020. The downstream areas had higher levels of ESs, while the upstream regions showed comparatively lower levels. This trend was particularly evident in areas with extensive arable land, higher population density, and more developed economic activity, where ESs levels were lower. (2) Trade-offs/synergies: The analysis highlighted the prevalence of synergistic effects among ESs, with food provisioning-related services exhibiting notable trade-offs. Trade-off/Synergistic effects were weaker at the grid scale but more pronounced at the sub-basin and county scales, with significant spatial heterogeneity. (3) Identification of ESBs: We identified five distinct ESBs: the HQ-CS synergy bundle (HCSB), the integrated ecological bundle (IEB), the agricultural bundle (AB), the key synergetic bundle lacking HQ (KSB), and the supply service bundle (SSB). These clusters suggest that the overall ecological environment of the study area has significantly improved, the supply functions have strengthened, and ecosystem vulnerability has been effectively mitigated. Building upon the identified multi-scale spatiotemporal heterogeneity patterns of ESBs in the XRB, this study proposes an integrated framework for territorial spatial planning and adaptive land management, aiming to optimize regional ecosystem service provisioning and enhance socio-ecological sustainability.

The growing global population and increasing agricultural demands have made nitrogen fertilizers essential for modern agriculture. However, nearly 50% of applied nitrogen fertilizers are lost to the environment, causing pollution and greenhouse gas (GHG) emissions. Biochar-based fertilizers (BBFs), combining biochar with chemical fertilizers, enhance nutrient efficiency, boost crop yields, and reduce N2O emissions. However, comprehensive field studies on BBF impacts remain limited. This study uses a global dataset of BBF field experiments to build predictive models with three machine learning algorithms for crop yields and N2O emissions, and to assess BBFs’ potential to increase yields and mitigate emissions in China’s major crops. The artificial neural network (ANN) model outperformed random forest (RF) and support vector machine (SVM) in predicting N2O emissions (R2: 0.99; EF: 0.99), while all models showed high accuracy for crop yields (R2, EF: 0.98–0.99). Variable importance analysis revealed that BBF C/N and BBF N/Mineral N explained 4.25% and 3.95% of yield variation, and 3.19% and 0.55% of N2O emission variation, respectively. BBFs could increase China’s major crop yields by 4.3–5.0% and reduce N2O emissions by 3.7–6.3%, based on simulations. Challenges like high costs and limited adaptability persist, necessitating optimized production, standardized protocols, and expanded trials.

Due to its high nutrient utilization efficiency, liquid organic fertilizer has become a research hotspot in the field of agricultural planting. Artificial humic acids, which are near-nature products, can be deemed as a green liquid organic fertilizer, but few studies have been reported, which has limited their further application. In this study, artificial humic acids were derived from municipal sludge, and their effect on rice growth, soil fertility, and dissolved organic matter was investigated using multi-chamber root box experiments. The shoot and root biomass of rice can be significantly enhanced by artificial humic acids, and the heavy metal concentration in rice was within safe limits. Artificial humic acids can limit the decrease in soil pH, especially in the far-rhizosphere zone, and improve the distribution of nutrients in the rhizosphere, near-rhizosphere, and far-rhizosphere zones. The use of artificial humic acids led to a significant decrease in soil electrical conductivity. The dissolved organic carbon content in the root zone was significantly increased, and the fluorescence intensity of dissolved organic matter in the rhizosphere was significantly increased. The proportion of specific components of dissolved organic matter was just slightly changed in the rhizosphere and near-rhizosphere zones. Artificial humic acids promoted the humification of dissolved organic matter in the near-rhizosphere and far-rhizosphere zones. The findings indicate that the environmental impact of artificial humic acids is significantly different from conventional chemical fertilizers, and they show huge potential in the agriculture field.

Organic fertilization is considered an effective approach in promoting agricultural green development, dramatically affecting soil phosphorus (P) availability. Nonetheless, limited information is available on the comprehensive impact of full substitution of organic fertilizer for chemical fertilizer on P speciation, phytoavailability, and apparent balance throughout different rice-growth stages. To address this gap, a 5-year field experiment was conducted, implementing five organic P gradients ranging from 0 (P-0), 70 (P-70), 140 (P-140), 210 (P-210) to 280 (P-280) kg P2O5 ha(-1) of organic fertilizer. To assess P phytoavailability in the root zone with submillimetre spatial resolutions, this study employed techniques such as the one- and two-dimensional diffusive gradients in thin films (DGT) technique and the high-resolution soil solution sampling technology (HR-Peeper). The findings revealed that increasing P rates enhanced soil Olsen-P and biological-based P fractions across rice-growth stages, primarily driven by variation in mineral-associated P. Notably, the P140 treatment demonstrated the highest P uptake efficiency among the different rice-growth stages, with a significant increase in soil DGT-P, particularly in the 0-60 mm soil layer (p <0.05), providing tangible evidence for enhanced P uptake. Moreover, compared with higher P treatments (P-210 and P-280), the P-140 treatment markedly increased P use efficiency by 31.7% and 99.0%, respectively (p <0.05). Further, with a high ratio of DGT-P to Peeper-P and a low apparent balance of P, organic fertilization at the rate of 140 kg P2O5 ha(-1) effectively struck a balance between ensuring adequate P supply for yield stability and mitigating potential P loss risks. These results underscore the significance of optimal organic fertilization in enhancing agronomic benefits while reducing environmental risks. They offer valuable insights to support field P management strategies and government decision-making processes.

The global food crisis provides an impetus for agricultural green transformation via optimized fertilization methods. While organic substitution, green manure incorporation, and targeted fertilization sites have individually shown promise in enhancing rice yield, there is still a gap between optimized fertilization methods and achieving sustainable rice production. To explore the factors influencing rice yield across different fertilization strategies, we conducted a field experiment in Southern China encompassing five treatments, such as CK (no N input), RN (broadcasting urea with recommended N rates), RON (broadcasting organic-inorganic fertilizer with recommended N rates), RONS (side-deep placement of organic-inorganic fertilizer with recommended N rates), and RONSA (coupled RONS with Azolla [Azolla pinnata R. Brown]). Using a Minimum Data Set approach, we identified the primary variables influencing soil properties and rice production, with a focus on soil physicochemical characteristics and bacterial communities. Further, the soil properties index (SPI), calculated by multiplying the linear score with the weight of each variable, served as an indicator of soil properties variations. Our findings revealed that RONSA significantly increased the SPI by 21.1% compared with RN, predominantly because of higher soil labile organic carbon (LOC) and available N (SAN) fractions (p < .05). N uptake in rice plants (23.9%-28.4%) increased dramatically under RONSA leading to higher rice yield (11.0%-16.9%) and NUE (30.2%-36.1%) than RN (p < .05). The enhancement in soil properties, characterized by increased LOC, SAN fractions, and bacterial community diversity, was essential in boosting rice yields, with dissolved inorganic N emerging as the dominant contributor. In summary, our results highlight the effectiveness of integrated fertilization approaches in enhancing soil properties, subsequently leading to improved rice yields and NUE. This fertilizer strategy holds promise for guiding field fertilization practices and advancing sustainable rice production.

This study examines the fluorescence characteristics of dissolved organic matter (DOM) in soils from different periods of rice–crayfish integrated systems (RCISs) in China. Utilizing three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy, the study investigated the hydrophobicity, molecular weight distributions, and fluorescence properties of DOM in 2-, 5-, and 7-year RCIS operations, with rice monoculture (RM) serving as a control. The findings indicate that in the initial 2 years of an RCIS, factors such as rice straw deposition, root exudates, and crayfish excretions increase dissolved organic carbon (DOC) release and alter DOM composition, increasing the humic acid content in the soil. As the system matures at 5 years, improvements in soil structure and microbial activity lead to the breakdown of high-molecular-weight humic substances and a rise in small-molecular-weight amino acids. By the 7-year mark, as the aquatic ecosystem stabilizes, there is an increase in humic substances and the humification index in the soil DOM. These variations in DOM properties are essential for understanding the effects of integrated farming systems on soil quality and sustainability.

The synthesis of ammonia through nitrate reduction has received increasing attention due to its ability to simultaneously achieve wastewater treatment and energy production. This study investigated the mechanism of high concentration nitrate reduction processes using Fe/Fe2+ process. Batch tests were carried out in high level nitrate reduction in Fe/Fe2+ system with different particle size iron powder to investigate the evolution of ni-trate, nitrite, ammonium, nitrogen balance, and pH in the liquid phase. The characterization results showed that the solid products were gamma-FeOOH when ZVI and nitrate react with lower activity. With the increasing of reduction reactivity, green rusts (GRs) generated and divided the reduction process into two phases. ZVI transformed into GRs and finally produced Fe3O4. The generation pathways of GRs in this study were mainly consist of the partial oxidation of Fe2+ and the hydrolysis of Fe2+ combing with the oxidation of Fe(OH)2. The reactivity between ZVI and nitrate plays a pivotal role in the formation of GRs. This study has provided a more comprehensive explo-ration of the formation mechanism of green rust during nitrate reduction.

Urban ecological spaces are effective thermoregulators under global warming. However, the cooling efficiency of urban ecological spaces during the urbanization has not been studied comprehensively. Here, we investigate the spatio-temporal dynamics of Urban Cold Island (UCI) intensity in 11 typical cities of the Yangtze River Economic Belt (YREB). We determined the impact of ecological landscape trends on these dynamics by using GlobalLand and MODIS 8 d mean land surface temperature (LST) data for three periods (2000, 2010, and 2020), and the landscape pattern index and diversity index. We found that in the past 20 years, the built-up area has increased by sixfold; 62.53 % and 37.47 % of YREB were warming or cooling, with 71.22 % of the daytime cooling and 93 % of the nighttime warming. The average UCI intensity of YREB has increased from 0.518 to 0.847 and is negatively correlated with LST with a decreasing slope. As the UCI intensity of green spaces increased, that of blue spaces decreased. Surface area and landscape pattern are the key determinants of UCI intensity in blue and green spaces, respectively, especially the landscape shape index (LSI). Therefore, maintaining ecological spaces, enriching the structural integrity of green spaces, and improving blue space connectivity can help cities at different development levels cope with heat stress during regional urbanization.

Biochar and hydrochar have garnered widespread attention owing to their excellent performance in environmental remediation, carbon sequestration, and resource utilization from biowaste. Studies on the release potential of dissolved organic matter (DOM) have been limited, and the distinction between biochar and hydrochar remains unclear. In this study, pine sawdust was utilized as a model precursor with the aim of comparing the release quantity, components, and properties of DOM from biochar (BDOM) and hydrochar (HDOM) under various simulated conditions. The amount of DOM released by hydrochar (38.20-190.49 g/kg) was significantly greater than that released by biochar (0.57-11.96 g/kg), and more DOM was released at higher temperatures and pH values. BDOM consists of three categories of components, namely, humic-like, protein-like, and benzoic acid-like and tyrosine-like substances compounds, whereas HDOM consists of four categories of components, namely, two categories of humic-like compounds and two categories of protein-like compounds. By using ESI-FT-ICR-MS technology, 8586 compounds in BDOM and 6428 compounds in HDOM were identified. A total of 4665 unique compounds were found in BDOM, 1416 unique compounds were found in HDOM under alkaline release conditions, and HDOM contained more unique compounds than those found in other environments. CRAM/lignin-like compounds made up the majority of the released DOM and reached 31.01-65.35 % for BDOM and 54.79-73.05 % for HDOM. These findings revealed significant differences in the release potential of DOM from biochar and hydrochar, and further behavior research is needed to guide future applications of char materials in the environment and agriculture fields.

The complex composition and heterogeneous nature of food waste limit the application of biochar materials derived from it in supercapacitors. In this study, biochar was prepared from simulated food waste using a hydrogel template and employed to fabricate supercapacitor electrodes. Food waste was first transformed into a soluble state through an advanced oxidation process (potassium persulfate/heat). Small-molecule polymerization was then performed to generate a structurally uniform food waste hydrogel (FWH). Urea was added during the synthesis of FWH to achieve the uniform incorporation of nitrogen into its structure. FWH biochar (FWHB) was obtained from FWH via pyrolysis at different temperatures (500, 700, and 900 degrees C). Then, we evaluated the physicochemical properties and electrochemical performances of the obtained FWHB samples. The FWHB pyrolyzed at 700 degrees C (FWHB700) exhibited a unique sponge-like microstructure with a high specific surface area of 693 m2 & BULL;g 1, which was 20 times that of untreated food waste biochar. FWHB700 also showed excellent energy storage performance, with a specific capacitance of up to 461 F & BULL;g 1 at a current density of 1 A & BULL;g 1. Based on physicochemical analysis and density functional theory calculations, the energy storage capacity of FWHB700 was found to be related to its high specific surface area, developed pore structure, as well as abundant nitrogen defects and heteroatom active sites. The symmetric FWHB700//FWHB700 supercapacitor delivered a high energy density of 9.99 Wh & BULL;kg 1 at a power density of 125 W & BULL;kg 1, with 88.2 % capacitance retention after 10,000 charge-discharge cycles. In summary, this study introduces a promising electrode material for energy storage and provides a new approach for the efficient utilization of food waste resources.

Biowaste-derived hydrochar is an emerging close-to-natural product and has shown promise for soil improvement and remediation, but the environmental behavior of the dissolved organic matter released from hydrochar (HDOM) is poorly understood. Focusing on the typical mulch film plasticizer diethyl phthalate (DEP), we investigated the effect of HDOM on the sorption behavior of DEP on soil. The relatively low concentration of HDOM (10 mg L-1, 25 mg L-1) decreases the sorption quantity of DEP on soil, while it increases by a relatively high concentration, 50 mg L-1. The transformation from multilayer to monolayer sorption of DEP on soil occurs as the concentration of HDOM increases. The tryptophan-like substance is the main component of HDOM sorbed to soil, reaching 49.82 %, and results in competition sorption with DEP. The soil pores are blocked by HDOM, which limits the pore filling and mass transfer of DEP, but partitioning is significantly enhanced. The surface functional groups in HDOM are similar to those in soil, and chemical sorption, mainly composed of hydrogen bonding, exists but is not significantly strengthened. We identified the specific impact of HDOM on the sorption of organic pollutants on soil and provide new insights into the understanding of the environmental behavior of hydrochar.

如何科学评估"绿水青山就是金山银山"(以下简称"两山")实践创新基地碳源碳汇的变化趋势、时空分布、影响因子,对指导新时期生态文明建设具有重要作用.以浙江省宁海县为例,基于IPCC碳排放清单,测度宁海县碳汇量与碳排放量,分析区域碳汇的空间分布规律,并基于方差分解分析探究宁海县碳排放的影响因素.结果表明,宁海县碳汇量呈现逐年增加的趋势,2003—2018年从43.91万上升至49.40万t,其中,森林碳汇量占比为88.21％～91.12％;碳源量呈现平稳—急剧上升—波动下降—保持稳定的变化趋势,由2003年的154.17万变化至2018年的508.87万t.从碳汇量的空间分布来看,宁海县县域碳汇大致呈现西部>东南部>北部>中部的西高东低格局;宁海县碳排放可被社会因素、经济因素和"两山"建设驱动因素共同解释,3个因素对碳排放的共有解释度为60.86％,各因子的解释度表现为经济因素>"两山"建设驱动因素>社会因素.该研究为国家"两山"实践创新基地的碳源碳汇量核算提供了新思路,可为下一步政策制定和县域绿色发展提供参考.